A Geomorphic Comparison of an Attainment and an Impaired Stream in Vermont: Potash and Allen Brooks Jen Fullerton, Travis Smith, Joe Bartlett, Sarah Palmer, and Nat Morse Prepared for ENSC 202 May 13, 2004

Presentation Outline Methods/Site Selection Methods/Site Selection Reach Descriptions Reach Descriptions Results Results Discussion Discussion

Methods/Site Selection Chose attainment stream according to the watershed size of Potash Brook (~20 km 2 ) Chose attainment stream according to the watershed size of Potash Brook (~20 km 2 ) Selected 3 similar reaches on each stream using various stream characteristics determined by a site visit Selected 3 similar reaches on each stream using various stream characteristics determined by a site visit Bed Material Bed Material Riparian Vegetation Riparian Vegetation Sinuosity Sinuosity Stream Type Stream Type Completed Phase 1 (SGAT) and Steps 6 & 7 of Phase 2 of the Stream Geomorphic Assessment Completed Phase 1 (SGAT) and Steps 6 & 7 of Phase 2 of the Stream Geomorphic Assessment

Attainment Reaches – Allen Book

Impaired Reaches 1 & 2 - Potash Brook

Impaired Reach 3 - Potash Brook

Potash Reach One - Channelized and armored banks -Medium gradient riffle-pool -Riparian buffer greater than 100 ft

Potash Reach Two -Unconfined -Low gradient ripple-dune formations -Riparian buffer less then 100 ft

Potash Reach Three -Straightened and armored on the left bank -Transitions from a straightened moderate gradient to a wide deep pool formation -Riparian buffer less then 50 ft

Allen Brook Reach One -Medium gradient riffle-pool formations -Riparian buffer greater than 100 ft

Allen Brook Reach Two -Low gradient dune-ripple formations -Riparian buffer greater than 100 ft

Allen Brook Reach Three -Low gradient dune-ripple formations -Riparian buffer greater than 100 ft

Phase 1 Results Predicted impact score for adjustment process for each reach using SGAT (higher scores indicate greater degradation)

Phase 2 Results - RHA RHA scores for each reach (score of 20 indicates reference condition)

Phase 2 Results - RGA RGA scores for each reach (score of 20 indicates reference condition)

Composite Results Potash Brook Potash Brook Allen Brook Allen Brook Allen Brook 1 Attain ment RGA Conditi on RHA Conditi on Conditi on Score Stream Name Potash Brook Potash Brook Allen Brook Allen Brook Allen Brook 1 Attain ment RGA Conditi on RHA Conditi on Conditi on Score Stream Name Potash Brook Potash Brook Allen Brook Allen Brook Allen Brook 1 Attain ment RGA Conditi on RHA Conditi on Conditi on Score Stream Name Condition, RHA, and RGA scores for each reach

Composite Results Scatter plot with regression line for RHA vs. stream condition

Composite Results Scatter plot with regression line for RGA vs. stream condition

Composite Results Scatter plot with regression line for RHA vs. RGA

Factors Affecting Stream Quality Upstream land cover/land use vs. stream corridor integrity (Potash 1 vs. Potash 2 and 3) Upstream land cover/land use vs. stream corridor integrity (Potash 1 vs. Potash 2 and 3)

Issues with Stream Engineering Rip-Rap Rip-Rap Sediment deposition Sediment deposition Bank failure Bank failure Adjustments needed Adjustments needed Separate protocol Separate protocol More categories More categories

Using SGAT for Phase 1 Assessment Increased confidence in values due to reduced subjectivity in assessment Increased confidence in values due to reduced subjectivity in assessment Problems with SGAT Problems with SGAT 50 ft contour lines are not accurate enough for delineation of valley walls 50 ft contour lines are not accurate enough for delineation of valley walls

Beaver Activity Evidence of Beaver Activity in 5 reaches Evidence of Beaver Activity in 5 reaches (Potash 1, 2, & 3, Allen 2 & 3) (Potash 1, 2, & 3, Allen 2 & 3) May have lowered RHA and RGA scores May have lowered RHA and RGA scores Loss of riparian vegetation Loss of riparian vegetation Decreased bank stability Decreased bank stability

Conclusions Urbanization in lower Potash Brook watershed impacted the geomorphology of the stream Urbanization in lower Potash Brook watershed impacted the geomorphology of the stream Riparian buffers and stream corridor integrity are important in mitigating the effects of development on streams Riparian buffers and stream corridor integrity are important in mitigating the effects of development on streams Strategic watershed planning is needed to minimize the impacts of development Strategic watershed planning is needed to minimize the impacts of development

Acknowledgements Dr. Breck Bowden Dr. Breck Bowden Alex Hackman Alex Hackman Mike Kline Mike Kline Doug Burnham Doug Burnham Staci Pomeroy Staci Pomeroy